Sanitary stuffing box



April 11, 1957 w. J. CULMAN SANITARY STUFFING BOX 4 Sheets-Sheet 1 FiledApril 29, 1964 I NVENTOR.

BY W April 1967 w. J. CULMAN 3,313,550

SANITARY STUFFING BOX v Filed April 29, 1964 4 Sheets-Sheet 2 p *1 1 amiww a INVENTOR.

BY M fiumyf m April 11, 1967 w. J. CULMAN 3,313,550

SANITARY STUFFING BOX Filed April 29, 1964 4 Sheets-Sheet 5 [mot/4111111INVENTOR April 1957 w. J. CULMAN 3,313,550

SANITARY STUFFING BOX Filed April 29, 1964 4 Sheets-Sheet 4 iffd/P/Vi/S'United States Patent O 3,313,550 SANITARY STUFFING BOX William J.Culman, (Zincinnati, Ohio, assignor to The J. H. Day Company,Cincinnati, Ohio, a corporation of Ohio Filed Apr. 29, I964, Ser. No.363,397 Claims. (Ql. 2774) The present invention relates to mixingapparatus; and is particularly directed to a novel sanitary seal forsealing an opening in the wall of a mixer tank surrounding the agitatorshaft.

The present invention is concerned with mixing apparatus, such as ribbonblenders, horizontal mixers and the like, of the type which include ahorizontal agitator shaft which extends outwardly through two verticalend walls of the mixer tank. It is conventional in such horizontalmixers to provide stuffing boxes to seal the end tank walls against anyleakage along the agitator shaft.

One of the principal difficulties encountered with prior art seals isthat both the seals themselves and the areas of the shaft and tank wallsadjacent the seals are difficult to clean. In many cases, particularlywhere a mixer is used in the food or pharmaceutical industries, it isessential that the seal, agitator shaft and mixer tank walls bethoroughly cleaned at frequent intervals, often after each batch.

In the past it has required an excessive amount of time to dissassembleand remove the seals and subsequently to reassemble them. Moreover, withmany seals even after they have been disassembled it is still quitediiTicult to get at all parts of the agitator shaft and adjacent tankwall. Other prior art shaft seal constructions have had the disadvantagethat they required cumbersome and expensive components for effectingremoval of the shaft seal for cleaning purposes.

The principal object of the present invention is to provide a novelsanitary shaft seal which is highly effective to seal around the shaftin normal mixer operation and which ran be removed quickly and easily topermit cleaning of the seal, shaft and mixer wall when desired.

It is another object of the present invention to provide a sanitary sealwhich can be disassembled to permit cleaning and reassembled without theuse of any tools or power elements.

More particularly, the present invention contemplates a sanitary sealcomprising a head plate permanently mounted upon the exterior of thetank wall surrounding the agitator shaft opening. This plate carries aplurality of mounting studs and aligning pins which posstion and supporta retaining plate and split stuffing box which surround and are spacedfrom the agitator shaft. A split annular gasket is compressed betweenthe head plate and retaining plate to provide a radial seal. Thestuffing box surrounds and embraces a series of split packing ringswhich provide a seal along the shaft. The outermost surface of theserings is abutted by a split sleeve member which surrounds and engagesthe shaft and is disposed within the central opening of the splitstuffing box. The split sleeve is urged inwardly to compress the packingrings into sealing relationship with the shaft by means of an end platewhich receives the agitator shaft and is supported by two bolts carriedby the stufiing box. The stuffing box is secured to the head plate andthe head plate is in turn secured to the stufliug box by means of handwheels which rotatably engage the ends of the studs and boltsinterconnecting the respective members.

In order to disassemble the stuffing box for cleaning, a worker merelyremoves the hand wheels retaining the end plate. This end plate is thenshifted outwardly along the shaft. Next, the hand Wheels supporting thestutfing box are turned and disengaged. The two halves of the stufiingbox and split sleeve member are disengaged from the shaft packing andother elements of the seal. In the ext step, the split packing rings areremoved from the shaft and the stuffing box plate, or front retainingplate, is shifted outwardly over the shaft. This exposes the splitgasket which is also disengaged from the shaft. After this step, allportions of the agitator shaft both inside and outside of the side Wallare fully exposed for cleaning. Also, the opening in the side walladjacent to the shaft is exposed permitting the sidewall area to becleaned thoroughly. The various component elements of the seal whichhave been removed can also be cleaned prior to assembly.

One exceedingly important advantage of the present seal assembly is thatit can be disassembled without the use of tools, cleaned and reassembledin a very short time, for example less than five minutes.

A second important advantage of the present seal is that the packingrings are uncovered from the outer end and are also uncovered abouttheir periphery so that they can be pulled radially free from engagementwith the shaft making it unnecessary to slide the rings rearwardlyoutwardly along the shaft.

A still further advantage of the present sanitary seal is that it is ofextremely simple construction and requires a minimum of parts with nopower operators.

These and other objects and advantages of the present invention will bemore readily apparent from a consideration of the following detaileddescription of the drawings illustrating a preferred embodiment of theinvention.

In the drawings:

FIGURE 1 is a perspective view of a ribbon blender provided with a shaftseal of the present invention.

FIGURE 2 is a perspective View of the present shaft seal in its normaloperative position.

FIGURE 3 is a vertical cross sectional view taken through the seal ofFIGURE 2.

FIGURE 4 is an exploded perspective view showing the seal in adisassembled condition.

FIGURE 5 is a perspective view of the seal similar to FIGURE 4 showingthe seal with the stuffing box and packing removed to permit cleaning ofthe shaft.

FIGURE 6 is a vertical cross sectional view through the shaft and sealelements shown in FIGURE 5.

One typical machine provided with sanitary stuffing boxes of the presentinvention is shown in FIGURE 1. The unit there shown is a ribbon blenderIt although it is to be expressly understood that the present sanitaryseal can be used in conjunction with all types of blending and mixingequipment irrespective of the type of agitator provided.

More particularly, the blending or mixing apparatus comprises a tank 11having vertical end walls 12 and 13. These end walls are provided withsuitable openings, such as opening 14 (FIGURE 5), through which extendsan agitator shaft 15. Agitator shaft 15 is rotatably supported on twoend bearings 16 mounted on support flanges 17 extending outwardly fromend Walls 12 and 13. One end of shaft 15 is driven from motor 18 througha suitable drive indicated generally at 24). Since the details of thisdrive are conventional and constitute no part of the present invention,it is considered unnecessary to describe the drive in detail.

The agitator shaft 15 carries a suitably configurated agitator member,or members. These members may be mounted upon spiders attached to theagitator shaft interiorly of end walls 12 and 13. Again, the specifictype of agitator constitutes no part of the present invention. Theopenings 1% in end Walls 12 and 13 are sealed by means of sanitary seal21. This seal surrounds agitator shaft 15 exteriorly of each of the endwalls 12 and 13 and is disposed intermediate the end wall and bearing16.

The details of construction of the sanitary seal are best shown inFIGURES 2-4. Since the seals associated with end walls 12 and 13 areidentical, only the seal associated with wall 12 will be described. Moreparticularly, the seal assembly comprises an annular tank head plate 22.This head plate surrounds opening 14 and is preferably welded to endwall 12 as indicated at 23 and 24. Head plate 22 is provided with threethreaded bores which receive outwardly extending studs 25. It is to beunderstood that the studs are threaded tightly into the bores so thatthe studs do not loosen when handles are threaded over them in themanner explained below.

Head plate 22 is also provided with openings for receiving aligningdowel pins 26. These dowel pins are press fit or otherwise permanentlymounted within openings in the head plate 22 and extend outwardly fromthe plate parallel to studs 25 and the axis of shaft 15. When thesanitary seal is in its assembled condition, the outer face of headplate 22 is engaged by an annular gasket member 27. This gasket member,which is made of any suitable material such as white squeegee rubber, ispreferably out along one-half of the annulus to form a dovetail jointindicated at 28. Gasket member 27 is of substantially the same size ashead plate 22 and is provided with suitable openings 30 for receivingstuds 25 and aligning dowel pins 26.

Gasket member 27 is compressed between head plate 22 and stufling boxplate 31. Plate 31 is of annular configuration and is of substantiallythe same outer diameter as gasket member 27 and annular head box plate22. However, stuffing box plate 31 is provided with a central opening 32of substantially smaller radius than the central opening through thegasket and head plate 22. As is shown in FIGURES 3 and 4, stufling boxplate 31 is also provided with an annular shoulder 33 spaced fromopening 32 by an inwardly extending radial retaining flange 34. Plate 31is further provided with suitable openings 35 for receiving studs 25 andaligning pins 26.

Retaining flange 34 of the plate 31 functions as a forward abutment fora plurality of split Chevron packing rings 36 which surround shaft 15and engage it in sea]- ing relationship. The rings 36 are preferablymolded Teflon rings and are retained by split stufling box members 37and 38. As is shown in FIGURE 4, in the preferred embodiment thestufling box members are identical and are split along a horizontaldiametral line. Each of the stuffing box members comprise a radialflange 49 which is adapted to abut stufiing box plate 31. Each of theflanges 40 is provided with openings 41 for receiving studs 25. Also,each of the flanges 4t) terminates in an annular shoulder 42 adapted formating engagement with the shoulder 33 formed on plate 31.

Each of the stufiing box sections 37 and 38 also includes an annular orsemi-cylindrical section 43. The cylindrical section 43 is provided witha semi-circular inner face 44 adapted to surround and embrace Chevronpacking rings 36 and bronze split sleeve members 45 and 46. These splitsleeve members embrace shaft 15 and abut the outer face 47 of the endChevron packing ring.

Stufiing box sections 37 and 38 are held in position by means of handles48 which threadably engage the ends of studs 25. When tightened down,handles 48 force flanges 40 of the stuffing box sections against plate31, tightly compressing gasket member 2'7 between plate 31 and headplate 22.

Stufling box members 37 and 38 each include an outer flange portion 50.Each of these flange portions is provided with a vertical slot 51 andlug portions 52 disposed on each side of the slot at the outer endthereof. Lug portions 52 function to retain the heads 53 of bolts 54against rotation and to releasably retain the bolts within slots 51 inthe manner shown in FIGURES 3 and 4. Bolts 54 extend outwardly parallelto the axis of shaft 15. The bolts are also received within verticalslots 55 in end plate 56. This end plate is provided with a centralopening 57 surrounding the shaft and an annular shoulder 58 adapted toengage the outer end of split bronze sleeves 45 and 4%. End plate 56 isheld in place by means of handles 60 which threadably engage the ends ofbolts 54. When handles 66 are tightened, end plate 56 is urged inwardlyalong shaft 15 toward end wall 12. Consequently, split bearing sleeves45 and 46 are urged inwardly against Chevron packing rings 36compressing these rings to provide a tight seal surrounding shaft 15.

The present stuffing box and seal can be disassembled completely topermit cleaning of the mixer without the use of tools. Specifically, todisassemble the unit from its assembled position shown in FIGURES 2 and3, hand wheels 60 are rotated to loosen them on studs 54. Studs 54 arethen shifted rearwardly to disengage heads 53 from lugs 52 and studs 5are lifted free from slots 51 in flange 50 and slots in end end plate56. After these studs are removed, end plate 56 is shifted outwardlyalong shaft 15 to the position shown in FIGURES 5 and 6. Next, the fourhand wheels 48 are removed. This permits removal of stufling boxsections 37 and 38. Specifically, these stufiing box sections aredisengaged from bolts 25 and are pulled outwardly as indicateddiagrammatically in FIGURE 4. The split packing rings 36 are then pulledfrom the shaft and plate 31 is shifted outwardly as indicated in FIGURES5 and 6. Finally, gasket 27 is removed. This gasket can be completelydisengaged from the shaft by separating dovetail joint 28.

With the seal thus completely removed, the various components canreadily be cleaned. Also, agitator shaft 15 and the surrounding areas ofend wall 12 are fully exposed for quick and thorough cleaning. Followingthe cleaning operation, the parts are reassembled by reversing the stepsdescribed above.

From the foregoing disclosure of the general principles of the presentinvention and the above description of a preferred embodiment of theinvention, those skilled in the art will readily comprehend the variousmodifications to which the invention is susceptible. Therefore, I desireto be limited only by the scope of the following claims.

Having described my invention, I claim:

1. In a sanitary seal construction for a mixer of the type having ashaft passing outwardly through an opening in an end wall of said mixer,the shaft being rotatably journalled in a bearing spaced from said endwall, the novel combination which comprises an annular head platemounted upon said mixer wall surrounding said opening, a first annularretaining plate, a split annular gasket interposed between said annularhead plate and said retaining plate, a plurality of studs carried bysaid head plate extending outwardly from said plate parallel to saidshaft, said first retaining plate having openings receiving said studs,a split stuffing box having a radial flange in abutment with saidretaining plate and having openings for receiving said studs, said splitstuffing box having a cylindrical central opening surrounding said shaftand spaced therefrom, a plurality of knob members threadably engagingsaid studs for releasably securing said split stuffing box, a pluralityof packing rings surrounding said shaft and being disposed within thecylindrical central opening in said stuffing box, the innermost of saidrings being in abutment with said retaining plate, a split sleeve membersurrounding said shaft and being at least partially disposed within theopening in said stufiing box, said split sleeve member being in abutmentwith said packing rings, and means for forcing said sleeve against saidrings, said means comprising an end plate having a central openingreceiving said shaft, said end plate being in engagement with the end ofsaid split sleeve member, a plurality of elongated bolts carried by saidsplit stufling box and extending parallel to said agitator shaft, saidend plate being configurated to receive said bolts, and knob membersthreadably engaging the ends of said bolts, said knob members being inabutment with said end plate.

2. In a sanitary seal construction for a mixer of the type having ashaft passing outwardly through an opening in an end wall of said mixer,the shaft being rotatably journalled in a bearing spaced from said endwall, the novel combination which comprises a first annular retainingplate, a plurality of studs, means mounting sai studs fro-m said endwall, said studs extending outwardly from said end wall parallel to saidshaft, said first retaining plate having openings receiving said studs,a split stufiing box having a radial flange in abutment with saidretaining plate and having openings for receiving said studs, said splitstufling box having a cylindrical central opening surrounding said shaftand spaced therefrom, a plurality of knob members threadably engagingsaid studs for releasably securing said split stuffing box, a pluralityof packing rings surrounding said shaft and being disposed within thecylindrical central opening in said stuffing box, the innermost of saidrings being in abutment with said retaining plate, a sleeve membersurrounding said shaft and being at least partially disposed Within theopening in said stufling box, said sleeve member being in abutment withsaid packing rings, and means for forcing said sleeve against saidrings, said means comprising an end plate having a central openingreceiving said shaft, said end plate being in engagement with the end ofsaid sleeve member, a plurality of elongated bolts carried by said splitstufiing box and extending parallel to said agitator shaft, said endplate being configurated to receive said bolts, and knob membersthreadably engaging the ends of said bolts, said knob members being inabutment with said end plate.

3. In a sanitary seal construction for a mixer of the type having ashaft passing outwardly through an opening in an end wall of said mixer,the shaft being rotatably journalled in a bearing spaced from said endwall, the novel combination which comprises an annular head platemounted upon said mixer wall surrounding said opening, a first annularretaining plate, a split annular gasket interposed between said annularhead plate and said retaining plate, a plurality of studs carried bysaid head plate extending outwardly from said plate parallel to saidshaft, said first retaining plate having openings receiving said studs,two stufling box members abutting one another in a horizontal plane,each of said stufling box members having a radial flange in abutmentwith said retaining plate and having openings for receiving said studs,each of said stuffing box members having a semi-cylindrical concavitysurrounding said shaft and spaced therefrom, a plurality of knob membersthreadably engaging said studs for releasably securing said stufling boxmembers, a plurality of packing rings surounding said shaft and beingdisposed within the concavities of said stuffing box members, theinnermost of said rings being in abutment with said retaining plate, twosleeve members surrounding said shaft and being at least partiallydisposed Within the opening in said stufiing box, said sleeve membersbeing in abutment with said packing rings, and means for forcing saidsleeve members against said rings, said means comprising an end platehaving a central opening receiving said shaft, said end plate being inengagement with the end of said sleeve members, a plurality of elongatedbolts carried by said stufling box members and extending parallel tosaid agitator shaft, said end plate being configurated to receive saidbolts, and knob members threadably engaging the ends of said bolts, saidknob members being in abutment with said end plate.

4. In a sanitary seal construction for a mixer of the type having ashaft passing outwardly through an opening in an end Wall of said mixer,the shaft being rotatably journalled in a bearing spaced from said endwall, the novel combination which comprises an annular head platemounted upon said mixer wall surrounding said opening, a first annularretaining plate, a split annular gasket interposed between said annularhead plate and said retaining plate, a plurality of studs carried bysaid head plate extending outwardly from said plate parallel to saidshaft, said first retaining plate having openings receiving said studs,a split stufiin-g box split along a horizontal axis, said stufiing boxhaving a radial flange in abutment with said retaining plate and havingopenings for receiving said studs, said split stulfing box having acylindrical central opening surrounding said shaft and spaced therefrom,a plurality of knob members threadably engaging said studs forreleasably securing said split stufling box, a plurality of splitpacking rings surrounding said shaft and being disposed within thecylindrical central opening in said stufling box, the innermost of saidrings being in abutment with said retaining plate, a split sleeve membersurrounding said shaft and being at least partialy disposed within theopening in said stuffing box, said split sleeve member being in abutmentwith said packing rings, and means for forcing said sleeve against saidrings, said means comprising an end plate having a central openingreceiving said shaft, said end plate being in engagement with the end ofsaid split sleeve member, a plurality of elongated bolts carried by saidsplit stufiing box and extending parallel to said agitator shaft, saidend plate being configurated to receive said bolts, and knob membersthreadably engaging the ends of said bolts, said knob members being inabutment with said end plate.

5. In a sanitary seal construction for a mixer of the type having ashaft passing outwardly through an opening in an end wall of said mixer,the shaft being rotatably journalled in a bearing spaced from said endwall, the novel combination which comprises an annular head platemounted upon said mixer wall surrounding said opening, a first annularretaining plate, a split annular gasket interposed between said annularhead plate and said retaining plate, a plurality of studs carried bysaid head plate extending outwardly from said plate parallel to saidshaft, said first retaining plate having openings receiving said studs,a split stufling box split along a horizontal axis, said stufling boxhaving a radial flange in abutment with said retaining plate and havingopenings for receiving said studs, said split stufling box having acylindrical central opening surrounding said shaft and spaced therefrom,a plurality of knob members threadably engaging said studs forreleasably securing said split stuffing box, a plurality of splitpacking rings surrounding said shaft and being disposed within thecylindrical central opening in said stufling box, the innermost of saidrings being in abutment with said retaining plate, a split sleeve membersurrounding said shaft and being at least partially disposed within theopening in and stuffing box, said split sleeve member being in abutmentwith said packing rings, and means for forcing said sleeve against saidrings, said means comprising an end plate having a central openingreceiving said shaft, said end plate being in engagement with the end ofsaid split sleeve member, said stufling box having a second flangeremote from said radial flange, said second flange having two verticalslots formed therein and having lugs formed adjacent to the ends of saidslots, an elongated bolt carried by said slots, the bolts includingheads in engagement with said lugs, said end plate being configurated toreceive said bolts, and knob members threadably engaging the ends ofsaid bolts, said knob members being in abutment with said end plate.

References Cited by the Examiner UNITED STATES PATENTS 685,959 11/1901Ward 277-104 706,976 8/1902 Macindoe 277104 1,034,696 8/1912 Danie-ls eta1 277107 2,137,328 11/1938 Bissell 277-66 XR 2,837,356 6/1958 Beaman2774 3,076,655 2/1963 Washburn 277-4 SAMUEL ROTHBERG, Primary Examiner.

1. IN A SANITARY SEAL CONSTRUCTION FOR A MIXER OF THE TYPE HAVING A SHAFT PASSING OUTWARDLY THROUGH AN OPENING IN AN END WALL OF SAID MIXER, THE SHAFT BEING ROTATABLY JOURNALLED IN A BEARING SPACED FROM SAID END WALL, THE NOVEL COMBINATION WHICH COMPRISES AN ANNULAR HEAD PLATE MOUNTED UPON SAID MIXER WALL SURROUNDING SAID OPENING, A FIRST ANNULAR RETAINING PLATE, A SPLIT ANNULAR GASKET INTERPOSED BETWEEN SAID ANNULAR HEAD PLATE AND SAID RETAINING PLATE, A PLURALITY OF STUDS CARRIED BY SAID HEAD PLATE EXTENDING OUTWARDLY FROM SAID PLATE PARALLEL TO SAID SHAFT, SAID FIRST RETAINING PLATE HAVING OPENINGS RECEIVING SAID STUDS, A SPLIT STUFFING BOX HAVING A RADIAL FLANGE IN ABUTMENT WITH SAID RETAINING PLATE AND HAVING OPENINGS FOR RECEIVING SAID STUDS, SAID SPLIT STUFFING BOX HAVING A CYLINDRICAL CENTRAL OPENING SURROUNDING SAID SHAFT AND SPACED THEREFROM, A PLURALITY OF KNOB MEMBERS THREADABLY ENGAGING SAID STUDS FOR RELEASABLY SECURING SAID SPLIT STUFFING BOX, A PLURALITY OF PACKING RINGS SURROUNDING SAID SHAFT AND BEING DISPOSED WITHIN THE CYLINDRICAL CENTRAL OPENING IN SAID STUFFING BOX, THE INNERMOST OF SAID RINGS BEING IN ABUTMENT WITH SAID RETAINING PLATE, A SPLIT SLEEVE MEMBER SURROUNDING SAID SHAFT AND BEING AT LEAST PARTIALLY DISPOSED WITHIN THE OPENING IN SAID SHUFFIMG BOX, SAID SPLIT SLEEVE MEMBER BEING IN ABUTMENT WITH SAID PACKING RINGS, AND MEANS FOR FORCING SAID SLEEVE AGAINST SAID RINGS, SAID MEANS COMPRISING AN END PLATE HAVING A CENTRAL OPENING RECEIVING SAID SHAFT, SAID END PLATE BEING IN ENGAGEMENT WITH THE END OF SAID SPLIT SLEEVE MEMBER, A PLURALITY OF ELONGATED BOLTS CARRIED BY SAID SPLIT STUFFING BOX AND EXTENDING PARALLEL TO SAID AGITATOR SHAFT, SAID END PLATE BEING CONFIGURATED TO RECEIVE SAID BOLTS, AND KNOB MEMBERS THREADBLY ENGAGING THE ENDS OF SAID BOLTS, SAID KNOB MEMBERS BEING IN ABUTMENT WITH SAID END PLATE. 